package com.example.ssm;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class B implements A{
    @Override
    public void m() {

    }
}

class Test {
    public static void main(String[] args) {
        B b = new B();
        b.m();


        A a = new B();
        a.m();

        List<String> stringList = new ArrayList<>();
        Map<Integer, String> map = new HashMap<>();
    }
}
